Patch Chords stop being able to change colour (bug?)

I was wondering whether anyone else has had this problem. I’m working on a patch, and I like to keep my patch chords nice and colourful so I can see the data flow. At some random point, I lose the ability to change the colours of the patch chords, i.e., I select them, go to colour, click the colour, yet it does not apply the setting.

I’ve copy and pasted the same code into another patch and the colour setting works again. But after some time, it loses it’s ability to work.

My patch uses tabbed subpatchers. One thing I notice is that this problem tends to occur in the subpatchers and not the root patch.

Curiously, I noticed this for the first time the other day as well. Edited an old patch that I hadn’t opened in a while, couldn’t change the cord colors. I’m on Max 6.1.6, OSX 10.8.5 as well. The patch was originally created in an older Max version.